Facebook sued over the 'Like' button

Facebook is being sued over its use of the 'Like' button and other social networking features.

The lawsuit, filed last week and reported today by BBC News, claims that Facebook is infringing two patents owned by Rembrandt Social Media LP, a patent-holding company working on behalf of a dead Dutch programmer called 'Jos' Van Der Meer.

He had used them to build his social network Surfbook, which allowed people to share information with their friends and family.

According to papers filed by Fish & Richardson, Surfbook featured a 'Like' button for users to approve content. Van Der Meer died in 2004, and the patents later passed to Rembrandt.

Rembrandt is now suing Facebook, and another social media company called Add This, over alleged patent infringement.

The papers claim that Facebook was aware of the patents held in the name of Van Der Meer as it had cited them in its own applications to patent social network technologies.

"We believe Rembrandt's patents represent an important foundation of social media as we know it, and we expect a judge and jury to reach the same conclusion based on the evidence," said attorney Tom Melsheimer, counsel for Rembrandt and managing principal of Fish & Richardson's Dallas office.

Facebook founder Mark Zuckerberg famously agreed a multimillion dollar settlement with the Winkelvoss twins after they accused him of stealing their idea to launch the social network.